And danger did not sharpen my senses, either. The chaos was blurred, my limbs were wood; tears leaked from my eyes and hurt my chapped cheeks, I moaned wordlessly, I dragged myself and the cart on with only a last patching together of the will. Up a small scarp, by lifting the front of the cart and putting the wheels on the higher ground. Backtracking to avoid a long fissure. Righting the cart. Pulling one wheel over a four- centimeter pebble. And so that whole long day passed, in work like that, in the dreadful confused blur of a nightmare.

In the fanned horizontal beams of sunset I sat on a rock. I had intended to heat some soup, and eat my remaining candy, but I was too tired to move. I sat there and watched the light of my last sunset drain off the land. When the sun disappeared I felt the sobs in me that I was too tired to make. Above the horizon the diamond pattern of mirror suns cast a streetlight glow over the dark land. And there in the plum sky, so high that it was still lit by the sun, was a bird. I could see its broad wings catching the westerlies, dipping and flapping once or twice as it pursued the sun. Canyon hawk, or Arctic eagle. Or more likely a garok, a big Tibetan crow. A Martian bird. Manipulation of their gene stock made it possible for them to live. That bird is an idea, I thought. I felt my thirst, and stirred to get water from the cart. I needed to clean my suit of wastes, dump the flask in the cart for recycling. The idea floated over the chaos, observing it with hungry care. It must have been blown east by the wind. “Should be over the canyons with the foxes and moles. Nothing here but mouse hares and snow finches, living in the same holes together.” Winds filled my chest, I breathed in and out unevenly, the soaring bird wavered in my sight and then held firm. Flight is a miracle, you know; it was bold to think of it. “You are an idea, Nederland. And you had better eat some soup, or the planet will forget you.” I ate soup, crackers, candy, beef sticks. Drank a lot of water. I got out the cart’s little spyglass and turned it south. Through the glass I saw a low line of cliff, still catching mirror sunlight. My escarpment. And perhaps a green point on it, there to my left. I drank more water, feeling my rehydration. I had only six hours of oxygen left. I packed the pockets of my suit with food, water bottle, telescope. Then, leaving the cart behind (a find for some future archaeologist to ponder), I hiked south through the mirror dusk.

The bird still soared over me; I got a good look at its beak, and decided it was a garok. No disappearing vision this, but a real bird. I remembered then something I had once read, that it was not uncommon for solo climbers at high altitude to hallucinate a companion climber, ahead or behind on the pitch. Unhappily I banished the thought. I didn’t want to think about what had happened to me.

When the last mirror sun disappeared the temperature plummeted. Night-time temperature on Mars: forty degrees below zero. But there was no wind, my facemask and goggles were in place, and my suit’s heater and my exertions kept me warm. It was an odd sensation — the suit radiated heat all over my skin, while breathing turned my insides to ice.

For an hour or two I advanced cautiously, resolutely, checking my landmarks and watching every step. After that exhaustion and dehydration made me clumsy, and inexorably the cold expanded from my lungs through my body. Every breath tortured my sore throat. I was thirsty, and my water was ice; I was tired, and my bed was rock. In the night’s dark the floor of the chaos was a field of fanglike seracs, hanging overhead as if I ascended a stone glacier. My head and throat roared, I thought I might go blind with the ache of it. And I could not sit down and rest for fear of dying. A few steps, a standing rest; a few steps, a standing rest — and on forever.

Then I ran out of oxygen. My pulse tripped crazily, I was sure I was dying. What a stupid idea, I raged, to hike out here alone! What were you thinking? My body pumped air that was like dry ice in and out of me; my throat even lost its pain, or went beyond it. Here was the test: Could Martian air alone keep a man alive at night? Waves of faintness nauseated me and I saw the dim shadow world in pumping red, then in greens, and I leaned against a rock wall, all my powers focused on holding to consciousness. Breathing dry ice. Carbon dioxide, argon, inert gases, a fat dollop of oxygen — all at three hundred and ninety millibars, maybe four-fifty in Aureum — was it enough?

Apparently it was. For the moment. Enough to move? I tested it, and found I could walk. But now the cold was more penetrating than ever. I couldn’t think, and I could barely walk, but I was afraid to sit. So I staggered on, slowly freezing to death, and killing my brain with lack of oxygen. Hours passed, and I carried on. The oxygen deprivation induced a mild euphoria in me; not a euphoria of spirits, exactly, but rather a sort of physical lightness. I stepped, stood, swayed, all with the distinct impression that if I did not keep my balance I might float away.

And then dawn came. Archimedes burst over the horizon without warning, taking me completely by surprise. I had forgotten daytime. Chapped lips broke to blood in a deathly grin. “The sun… is an idea.”

And it showed me I had somehow kept hiking south. The escarpment was no more than two kilometers before me, and hiking toward it I saw off to my left the green flag. “Dead reckoning, all right.” My headache was gone, and I felt free to sit for a moment and rest. I nearly failed to stand again, but when I managed it I floated along fairly well, feeling quite relaxed. Just after sunrise proper I made it to the bottom of the cliff, where I considered the problem of the rope ladder. There was no way around it; I was going to have to climb the thing. I took three quick steps up and hung my arms over a rung until I caught my breath. Then I added two rungs, and hung against the scarp again; and did it again, and repeated the maneuver until every muscle screamed, and my lungs pumped fast as a bird’s. Getting over the edge was a technical problem that stopped me cold; but the idea of surviving the whole night and then falling at the last bend was too distasteful, and I lunged up and onto flat land. On hands and knees, without looking up, I followed the ladder to the car. Then through the lock — hard work — and into the inexpressibly warm air of the car. From my knees I switched on the car’s systems, and collapsed onto the couch. I looked out at the great sink of Aureum, flooded by the lemon light of a new day, and falling asleep I shook my fist at the scene. “I went as far as I could for you, Emma Weil!”

And so I had. I slept without stirring until late that day, when intense thirst roused me. I found I was almost too stiff to move: I had pulled a muscle behind my left knee, tendonitis locked my right, and my arms and armpits were bruised and sore from the ascent of the ladder.

I stripped off my suit, shuddering at the sour smell; tossed it in the laundry drawer, and went to the toilet to clean up. I stared at myself in the mirror, appalled. My beard was like a stubbled field, and sweat covered this field like a white frost. My cheeks and nose were cracked and whitish. “They’ll have to regrow that skin. Dr. Laird will be angry.” Beady eyes were sunken deep, the skin under them was black. So I would look on the last day of my life. So my corpse would appear. I splashed water onto my face and felt the sting voluptuously: water of life, sting of living.

I went back to the driver’s seat and looked out the window. Dusk in the chaos, brown- black shadows under a banded sky.

The violent purples of the world’s end. But it was just another day. Every day was a stroke on the calendar: live a thousand years, it was still true. I had lived my life as if I were immortal, but now I knew differently. Extend as far as I could, there would still come the day of the dysfunction, the radical breakdown, the end. And the face in the toilet mirror believed it.